This proposal describes a career development and training plan for Dr. Karen Levy, Assistant Professor in the Department of Environmental Health at Emory University's Rollins School of Public Health. Dr. Levy's career goal is to become an independent investigator in the epidemiology and ecology of infectious diseases with a focus on enteric diseases. The K01 mentored career development award will allow her to build on ongoing collaborations, develop relationships with new mentors, and have protected time to produce scientific manuscripts that will bolster her already strong publication record. Dr. Levy will receive training in molecular epidemiology and bacterial genetics by (1) participating in a series of short courses; (2) gaining experience and training in microbial genomics; and (3) receiving mentoring from an exceptional team of senior faculty. Through this training program, Dr. Levy will increase her capacity to integrate social, epidemiological, and molecular data towards understanding mechanisms of infectious disease transmission and spread. Her mentoring team includes experts in infectious disease epidemiology: Drs. Uriel Kitron and Les Real at Emory University and Dr. Betsy Foxman at University of Michigan. ENVIRONMENT: Emory University provides an excellent venue for Dr. Levy to develop a career as an independent investigator and the university has signaled its commitment to Dr. Levy's career development. Emory's strengths in water and health studies and disease ecology make it especially suited to incubation of a career in the epidemiology of enteric diseases. RESEARCH: The proposed research project will use fine-scale genetic data to understand transmission processes at multiple spatial scales, from local to country-wide, affecting the distribution of diarrheagenic E. coli strains in the Borbon region of the Ecuadorian province of Esmeraldas. The goal of the research is to investigate the role that human travel between urban and rural regions plays in determining the distribution of circulating strains of pathogenic E. coli. This is important because the strains in circulation affect the occurrence of diarrheal illness in na?ve populations. The research approach combines a classic epidemiological case-control study design with whole genome sequencing, phylogenetic analysis, and data on human movement to address the following Specific Aims: (1) Investigate travel as a risk factor for enteric diseases, specifically diarrheagenic E. coli; (2) Examine the role of a regional population center as a common hub of diarrheagenic E. coli strains circulating in outlying rural villages; (3) Investigate parallels between genetic similarity of pathogenic E. coli strains and human movement patterns on a country-wide scale. This research will widen the lens by which to view and design optimal control strategies for the control of enteric diseases. The results will provide insights into whether investing in infrastructure to control pathogens in dense population centers could also affect conditions in outlying rural areas by limiting regional circulation of diverse strains of diarrheagenic E. coli.